Question

Which statements describe dark matter? Check all that apply.

Answer 1

Dark Matter is just matter that doesn't interact via the Electromagnetic (EM) or Strong Nuclear forces. No EM interactions means that it can't give off light, or absorb light, or reflect, refract, or scatter light in any way. This, naturally, makes it rather difficult to see (thus "dark" matter, although I suppose it's more "transparent" than "dark"). Our current best measurements indicate that something like 85% of the matter in our observable Universe (about a quarter of the total mass-energy content) is Dark Matter.

Answer 2

Roughly 80% of the mass of the universe is made up of material that scientists cannot directly observe known as Dark Matter, this bizaare ingredients does not emit light or energy.